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The key to Mack's contract is the generous structure, Rapoport was told. The first two years of the pact are fully guaranteed, with plenty of cash also coming in Year 3. Mack was helped by the fact that both the Chargers and Browns were in hot pursuit of the eighth-year veteran.

Chalk it up as a major signing for Atlanta, strengthening the club's offensive line with one of the league's grittiest interior maulers. Outside of missing 11 starts in 2014 with a broken fibula and ankle, Mack has started all 101 games of his career with the Browns.

There was hope in Cleveland that the team's newfangled front office would find a way to keep their trusty pivot, but Mack was a strong candidate to bounce after voiding his contract with the bottom-feeding Browns.

Undoubtedly, Falcons play-caller Kyle Shanahan also put in a good word for Mack after they worked together in Cleveland in 2014. He's an ideal fit for Shanahan's zone-blocking scheme and a serious upgrade over Mike Person, who struggled at center last season. It's also great news for Shanahan's cast of running backs led by Devonta Freeman and Tevin Coleman.

Mack, at last, has the chance to play with a franchise quarterback for the first time since the Browns made him their first-round pick in 2009. Enduring countless coaches, general managers and half-baked signal-callers in Cleveland, Mack and Matt Ryan are an ideal match in Atlanta.

The 30-year-old Mack struggled for parts of last season, but he's operated as one of the league's top centers from Day One. The money will be steep for a player of his age, but Mack has an excellent chance to finish out his deal as a reliable anchor along Atlanta's O-line.

The Browns, meanwhile, are watching another key player walk out the door.